Cluster headaches are rare, but are the most painful of the headaches known as “primary headaches”. Effective treatments during the headache are the triptan class of drugs or inhaled oxygen.
What is Cluster Headache?
Cluster headache is a most painful form of headache. Patients commonly describe cluster headache as the worst pain they have ever experienced. Cluster headaches are typically one-sided and tend to occur in clusters (groups) over a period of weeks or months. About 3 of 1000 people have cluster headaches with males being affected more than females. Onset is commonest between 20 to 40 years of age.
Diagnosis is made based on a careful medical history without the use of expensive diagnostic tests. The emphasis is on pain, timing and other distinctive features unique to cluster headache. The International Headache Society describes cluster headache as ’attacks of severe, strictly one-sided pain which last for 15 to 180 minutes which occur from once every other day to eight times per day’. It is associated with one or more of the following symptoms: red eyes, tears, nasal stuffiness or pain, forehead and facial sweating, dilated pupils and eyelid drooping or swelling.
How are cluster headaches treated?
Whatever the therapy, patients with cluster headache will be concerned and need support and reassurance. Although cluster headaches are painful and frustrating, there are many effective treatments available.
Conventional analgesics, or pain killers, have no place in the treatment of cluster headache. A specific treatment plan needs to be put together by the GP often in conjunction with a specialist in a hospital. Known triggers for cluster headache are smoking and alcohol so these are strongly discouraged in the cluster headache sufferer.
Treatment for cluster headache attacks can be either preventative or acute. Preventative treatment aims to decrease the incidence of attacks; acute therapy is directed at alleviating the symptoms of an individual attack when it occurs.
Preventative treatment should be started early and can be combined with acute treatment. Not every drug is effective in each patient and, as with all medications failure with one drug does not predict failure with others. All of the dugs listed can be tried if necessary. Drugs with known efficacy in preventing cluster headache are verapamil and methylprednisolone. To a lesser extent drugs like lithium and ergotamine are also used. Some of these drugs have known side effects which can be harmful so they should only be taken under guidance of a doctor after the risks and benefits have been weighed up.
Given the severity of the headache, rapid onset and short time to peak intensity, acute therapy has to be swift and effective. First-line therapy includes inhaled oxygen and the triptan class of drugs.
For every three participants treated with a triptan, at least one would be expected to gain headache relief who would not have done so without the drug. For every four treated, at least one can be expected to be pain-free within 30 minutes. Triptans are at their most effective if the injectible variety (subcutaneous sumatriptan) is used. They can also be inhaled nasally (intranasal zolmitriptan) although this preparation is not as effective. A potential draw back with the triptans is that they can only be used two to three times a day and they may not be safe in heart disease. For this reason inhaled oxygen has been studied.
Treatment of patients with cluster headache at symptom onset using inhaled high-flow oxygen is likely to result in the patient becoming pain-free compared with patients who breathe room air. This treatment can be repeated on demand without fear of side effects. However, it can be cumbersome and is clearly not recommended in those that smoke.
Non drug treatment
When preventative and acute therapy is commenced, and until doses considered to be useful are achieved, therapy using nerve blocks is sometimes used but this is without good evidence of efficacy. Surgical options include implantation of occipital nerve or deep brain stimulator but these techniques need special consideration.
In summary, effective treatments are available for cluster headaches. A combination of treatments may offer the most ideal therapy. The triptans may be the most useful treatment option in acute cluster headache, offering convenience over oxygen therapy.
British Association for the Study of Headache (BASH), www.bash.org.uk
Cluster headaches - patient.co.uk site
Useful scientific references
Triptans for acute cluster headache. Law S, Derry S, Moore A. Cochrane data base of reviews 2010.
High-Flow Oxygen for Treatment of Cluster Headache: A Randomized Trial, Cohen A, Burns B, Goadsby P JAMA. 2009;302(22):2451-2457
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Page updated 15/02/2016